Where it comes from
It sits next to the 'Quaid army' / 'righteous kill' call-and-response, which comes from the show's Total Recall bit.
How the hosts use it
Used as a label for pod haters, and jokingly for hosts who sound like haters (Andy is said to have 'established firmly he's a hauser'). In Ep. 59 the hosts circle the coincidence that Quaid's alter-ego is Hauser, Doogie's surname is Howser, and Doogie's first name is Douglas, so they treat it as a puzzle.
Why fans love it
It is a deep-cut Total Recall reference stacked on the Doogie Howser coincidence. The hosts mix up the spelling (Hauser, Houser, Howser) and what the character is, and get confused about whether they themselves love or hate the pod.
Written by the AI from the transcripts. Every sentence was checked against them, one by one (the full episode transcript wherever a sentence names one); 2 sentences that failed the check are left out. How the check works.